The present invention relates generally to the field of radio frequency (RF) communications, front end units, and transceivers, and more particularly to RF switches for selecting between transmit and receive modes in wireless communications.
Switches used in selecting between transmit and receive modes are typically of the single pole, double throw (SPDT) type. An SPDT is a configuration of two series-shunt branches, each consisting of stacked field effect transistors (FETs). The series branches, to which the shunt branch is not connected, are tied together at one end and are usually connected to an RF antenna. The other ends of the series branches connect to different ports, typically, the transmit and receiver ports, forming a double throw configuration. Performance metrics of RF switches include: (i) insertion loss; (ii) switch isolation; (iii) power handling capability; (iv) harmonic power levels; and (v) form factor.